Wireless energy transfer systems are known to incorporate a first resonator structure, hereafter referred to as a source resonator, which includes a coil configured to transfer magnetic energy and a spaced apart second resonator structure, hereafter referred to as a capture resonator that also includes a coil but is configured to receive the wirelessly transmitted magnetic energy. Such a wireless energy transfer system may be used for electrically charging an energy storage device or battery of an electric or hybrid vehicle. In such a system, the source resonator may be located on a ground surface, such as on a floor of a garage or a surface of a parking lot, and the capture resonator may be disposed on a vehicle.
During operation of such a wireless energy transfer system, the vehicle to be charged is parked so that the capture resonator is generally aligned above the source resonator. The capture and source resonators are separated by a distance that approximates a ground clearance of the vehicle which is a typical clearance between the bottom portion of the vehicle's chassis and a ground surface. In some vehicle applications, the ground clearance may be in a range from about 10 centimeters (cm) to 20 cm. In such an arrangement, this ground clearance space between the source and capture resonators is large enough to provide room for small animals, such as dogs and cats, and other possible foreign objects, such as aluminum soda cans or tools to reside. It is desirable to keep such animals and foreign objects out of this space between the aligned capture and source resonators during operation of the wireless energy transfer system, for example to enable maximum energy transfer efficiency from the source resonator to the capture resonator.
Thus, a robustly constructed cover employed on a source resonator is needed so as to discourage animals and foreign objects from coming to rest and overlie the source resonator to ensure maximum energy transfer efficiency in an electrical charging system.